* call remove_done_callback in finally section

* Optimize get_event_loop and _get_running_loop

* rename _loop_pid as loop_pid and add blurb news

* rename _loop_pid as loop_pid and add blurb news

* add back _RunningLoop

* Update 2017-09-05-10-30-48.bpo-31350.dXJ-7N.rst

* Update 2017-09-05-10-30-48.bpo-31350.dXJ-7N.rst